Genomics: the new map of life.

• Author: Tally, Steve
• Position: Science & Technology

THE STATE OF THE ART in life science--biology, medicine, and agriculture--resembles the situation geographers found themselves in centuries ago. Early cartographers had a small bit of information and tried, with obvious errors, to produce a view of what the world looked like. The maps of that era were equally off target, with misshapen or missing continents and dire warnings about the dangers and dragons that existed in the unknown waters.

A teacher in the third century A.D., Lactantius Firmianus, said, "Can there be a place on Earth where things are upside down, where the trees grow downwards, and the rain, hail, and snow fall upward? The mad idea that the Earth is round is the cause of this imbecile legend." Although early concepts of the world are comical today, those ideas of how the world worked were then quite reasonable, given the information they had.

Just as explorers such as Christopher Columbus, Ferdinand Magellan, and Hernando Cortes brought rapid change to the understanding of the Earth, a new field of biology promises to bring great and fast strides into the understanding of living organisms. The new area of study focuses on the genes of living organisms, first by mapping out the structure of all of the individual genes of the organisms, then by figuring out what all of those thousands of genes actually do. This new map of life is called genomics.

"It's quite a change to think that any of this is possible," indicates Jeffrey Bennetzen, Purdue University's H. Edwin Umbarger Distinguished Professor of Genetics. "Six or seven years ago, we wouldn't have even thought about doing these genomics experiments." Over the past few years, however, new laboratory techniques have been developed that allow scientists to make discoveries that just a decade ago seemed impossible.

The genomics revolution has been spurred in part by new automated machines that can quickly determine the structure of genes. "Before, it might have taken us two years to determine the structure of one particular genome," Bennetzen notes. "Now, we expect to do the same region in a couple of weeks."

Before genomic techniques were developed, if a scientist was interested in finding the genes that caused a certain trait, it was not unheard of for him to spend his entire career identifying those genes. That process required painstakingly comparing the genes of the plant or animal that had the trait with the genes of those in which the trait was lacking.

With genomics, scientists take a different approach. They use automated equipment to map out rapidly the sequence of all the genes in an organism. Then, in a step that is still somewhat painstaking, they go back and figure out what each of those genes does.

Although the gene sequencing of important organisms is obviously a finite activity, Randy Woodson, director of Purdue's Office of Agricultural Research Programs, maintains that genomics is a field of science that will be around for decades to come. "The science of genomics isn't going to be over tomorrow. There will be a five- to 10-year period of intense activity, especially in the sequencing of genes. At that point, we will have come full circle and come back to a point where physiology and biochemistry and other sciences will be needed to understand the...